While social conservatives view homosexual conduct as the most important aspect of sexual orientation for public policy debates, the question of the origin and nature of same-sex sexual attractions is an important scientific issue that lays the foundation for an understanding of homosexuality.

The “gay identity” paradigm is based on a belief or assumption that same-sex attractions develop because of a biological (and likely a genetic) characteristic that is present from birth and cannot be changed during the life course.  The following video from National Geographic explains this view.

While this belief is widespread, the empirical case for it is actually quite weak.  In the early 1990s, there was a great hope in some circles that a “gay gene” would be found that would prove homosexuality to be fixed and determined genetically.  This enterprise has proved to be a notable failure.[i]

This is not to say that there is no genetic influence on the development of same-sex attractions – but there is a significant difference between a trait being genetically influenced and genetically determined.  In fact, the latest research involving identical twins (who have an identical genetic makeup) has shown such low concordance rates (the percentage of cases in which both twins are homosexual when at least one of them is) that the idea of homosexuality as a fixed, genetically determined trait must be considered to have been disproved.[ii]

Some researchers have suggested non-genetic biological theories for the origin of same-sex attractions, such as homosexual influences or intrauterine experiences.  However, none of these can be said to have been definitively, scientifically proven.  They remain the subject of legitimate scholarly debate.

So if people are not “born gay,” where could same-sex attractions come from?  Most researchers prior to the 1970’s believed, as many still do today, that such attractions are primarily a developmental result of childhood experiences.  This is not to say that there is any one pattern of childhood experience that always results in homosexuality, nor that there is any one such pattern that is common to the personal histories of all those who do develop same-sex attractions.  Nevertheless, there are some patterns that appear frequently in the life histories of those with same-sex attractions.  These include poor bonding with the same-sex parent or peers,[iii] or child sexual abuse.[iv]

These varied findings help illuminate how misguided is the question which is sometimes posed about the origins of homosexuality: “Are people born gay, or do they choose to be gay?”  Contrary to stereotype, social conservatives do not assert that people “choose to be gay” (if “being gay” is defined merely as “experiencing same-sex attractions”).  If same-sex attractions result from developmental forces in childhood, then they are neither “inborn” nor “chosen.”

The American Psychological Association has taken strongly pro-homosexual policy stances – yet even they acknowledge that multiple factors probably influence the development of same-sex attractions.  They declared in 2008:

“There is no consensus among scientists about the exact reasons that an individual develops a heterosexual, bisexual, gay, or lesbian orientation…. Many think that nature and nurture both play complex roles; most people experience little or no sense of choice about their sexual orientation.”[v]

However, while people do not “choose” to experience same-sex attractions, they do choose whether or not to engage in homosexual conduct (and also choose whether or not to publicly self-identify as gay, lesbian, or bisexual).  The position of social conservatives is that all people – including people who experience same-sex attractions – should choose to abstain from engaging in homosexual conduct, because of the harms associated with that conduct.